Ultrasonic spray pyrolysis synthesis of Al, Zr, and Ti oxides multishell

In recent years, core shell nanoparticles have received increased attention due their possible applications in catalysis, biology and materials science. Solid micro-particles with a nanostructure of concentric multilayers were obtained with spray pyrolysis technique. In this work we present the synthesis and characterization of 1 to 10 layers of micro-spheres deposited on commercial brass sheet. Each layer is formed by three films: the first one is made of aluminum oxide, the second of zirconium oxide and the last film of titanium oxide. The films were deposited by the ultrasonic spray pyrolysis technique using organometallic salts of aluminum, zirconium and titanium, employing N, N-dimethylformamide as solvent. Scanning electron microscopy micrographs of 7 and 10 layers shows details about the formation of the layers. The micro-spheres are compacted in a homogeneous and uniform film, whose hardness increases with the number of layers.